The present invention relates to a resin material for inserting therein a lead frame. More particularly, the present invention is concerned with a resin material for inserting therein a lead frame and which resin exhibits an improved adhesion to the lead frame and has excellent heat resistance, moldability and other general properties. The invention is further concerned with a molded component comprising the above-mentioned resin material and a lead frame inserted therein.
As a method of mounting electronic components on a printed board, recently, a surface packaging technology using an infrared oven, which can realize a higher packaging density, is being widely used in place of the method wherein the terminal of an electronic component is passed through a hole of a printed board and then soldered to the rear of the board. In accordance with this trend, plastic packages for electronic components are usually required to have a high temperature of resistance up to which temperature the resistance to soldering heat is ensured. Moreover, the solvent used as a cleaning liquid for electronic components is usually a strong acid or a strong alkali, which makes it necessary for the printed board to have a solvent resistance sufficient to resist the solvent during the cleaning of electronic components. With respect to these requirements, polyarylene sulfide resin is the most suitable material as a plastic package for electronic components. However, polyarylene sulfide resin has a drawback inasmuch as the adhesion of polyarylene sulfide to a lead frame is poor. Accordingly, cleaning liquid penetrates into gaps between the lead frame and the plastic during the cleaning of electronic components and contaminates contacts. To cope with this drawback, it is a common practice in the art to take measures, such as to apply a primer or an adhesive to the lead frame prior to molding or to use an epoxy resin having a desirable adhesion to metal for potting at the root of the lead frame protruding from the package after molding.
However, such measures complicate the process and result in extreme cost increases. Therefore, a resin material having excellent adhesion to a lead frame has been desired in the art.